Horseshoe-shaped lifebuoy and method of making the same

ABSTRACT

A HORSESHOE-SHAPED LIFE BUOY AND METHOD OF MAKING THE SAME IN WHICH A SUBSTANTIALLY U-SHAPED BODY MEMBER HAVING A PAIR OF SPACED ARMS IS FORMED OF POLYSTYRENE FOAM MATERIAL OR THE LIKE. ONE OR MORE CUTS ARE MADE IN THE BODY MEMBER, WHICH CUTS EXTEND ACROSS THE ENTIRE THICKNESS OF THE BODY MEMBER INWARDLY FROM THE OUTER EDGE OF THE BODY MEMBER. THE CUTS PERMIT THE ARMS TO FLEX, SHIFT AND &#34;GIVE&#34; ALONG THE CUTS. THE BUOY CAN ACCORDINGLY WITHSTAND SEPARATION PRESSURE EXERTED AGAINST THE ARMS WHICH WOULD NORMALLY CAUSE IT TO BREAK OR CRACK. THE BODY MEMBER MAY BE COMPRESSED FOR ADDED STRENGTH.

y 25, 1971 J. H. ROBERTSON 3,579,683

HORSESHOE-SHAPED LIFEBUOY AND METHOD OF MAKING THE SAME Filed Aug. 15, 1969 James Aoer/san INVENTOR.

l/krm United States Patent O 3,579,683 HORSESHOE-SHAPED LIFEBUOY AND METHOD OF MAKING THE SAME James H. Robertson, 5238 Vineland Ave.,

North Hollywood, Calif. 91601 Filed Aug. 15, 1969, Ser. No. 850,432 Int. Cl. 1363c 9/10 US. Cl. 9340 12 Claims ABSTRACT OF THE DISCLOSURE A horseshoe-shaped life buoy and method of making the same in which a substantially U-shaped body member having a pair of spaced arms is formed of polystyrene foam material or the like. One or more cuts are made in the body member, which cuts extend across the entire thickness of the body member inwardly from the outer edge of the body member. The cuts permit the arms to flex, shift and give along the cuts. The buoy can accordingly withstand separation pressure exerted against the arms which would normally cause it to break or crack. The body member may be compressed for added strength.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to a horseshoe or U-shaped life buoy and to a method of making the same.

Description of the prior art Horseshoe or U-shaped life buoys are now conventionally made of polyvinyl chloride foam material because it is the only material which has suflicient resilience to withstand the pressure tests required for United States Coast Guard approval.

SUMMARY OF THE INVENTION This invention relates to a horseshoe-shaped life buoy and method of making the same from polystyrene foam material, which is far more economical than the polyvinyl chloride foam material now in use.

It is particularly an object of the invention to provide such a life buoy which has increased resilience above and beyond the conventional resilience of polystyrene foam material, so that the life buoy will successfully withstand the pressure tests required for United States Coast Guard approval.

In essence, my invention contemplates a molded polystyrene foam buoy of the type described in which the necessary added resilience is achieved by providing spaced cuts or breaks in the body of the material which spread the load. When pressure is applied to the body of the buoy, such pressure is successfully absorbed along the controlled break-lines without destroying the body of the buoy.

It is accordingly possible to form a buoy of more economical polystyrene foam material which has the resilience and strength required to pass the necessary tests. The buoy is accordingly more economical to manufacture and can be sold at a lower price, providing greater economy for the users.

The invention also comprises such other objects, advantages and capabilities as will later more fully appear and which are inherently possessed by the invention.

While I have shown in the accompanying drawings a preferred embodiment of the invention, it should be understood that the same is susceptible of modification and change without departing from the spirit of the invention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of my horseshoe-shaped life buoy;

FIG. 2 is a sectional view of the same taken along line 2-2 of FIG. 1;

FIG. 3 is a top plan view of the body member showing the cuts formed therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment which has been selected to illustrate the invention comprises a horseshoe-shaped body member 10, which is preferably formed of molded expanded polystyrene foam material. The material forming the body member 10 is preferably cut or molded in a thickness of 4" and then passed through rollers to compress it to a thickness of 3 /2" to provide greater strength.

After the body member 10 has been so formed, it is provided with a plurality of spaced cuts 11. The cuts 11 extend through the entire thickness of the body member 10 and extend from the outer edge of the body member 10 to a point approximately A" short of the inner edge of the body member 10.

In the embodiment shown in the drawings, five spaced cuts 11 are provided. Three extend substantially transversely across the area where the arms are joined and two are disposed adjacent to the free ends of the arms.

The purpose of the cuts 11 is to provide means for absorbing strain and stress which may be imposed upon the body member 10 in use. The United States Coast Guard test for U-shaped buoys provides that the buoy must withstand 200 lbs. of pressure directed against the arms.

If the cuts 11 were not present, this amount of pressure would inevitably cause failure of the body member 10 due to its cracking or breaking. I have found that by providing spaced cuts of the type described, the body member 10 can be made capable of withstanding such pressure without bending or cracking. This is believed to be due to the fact that a portion of the stress or pressure is absorbed by each of the joints created by the cuts, instead of all of the pressure and strain being concentrated at one point and causing cracking or breaking at the weakest point.

The cuts 11 also provide means for absorbing the stress through a limited degree of flexing, shifting and give which occurs along the cuts 11. Thus, if pressure is applied against the arms, the cuts 11 act to absorb such pressure and to divide or spread it, instead of allowing it to become concentrated and cause breakage at the weakest point. The cuts 11 in effect divide the body member 10 into a plurality of segments which are hinged by the uncut portions at the inner edges of the cuts 11. As shown by the dotted lines in FIG. 3 of the drawings, the cuts 11 preferably extend substantially radially from a point adjacent to the center of the body member 10.

When pressure is applied to spread the arms apart, each segment of the body member 10 pivots on the uncut portion of the body member 10 at the inner edges of the cuts 11 and exerts pressure against the adjacent segment along the lines of the cuts 11. The portions of the segments which are disposed along the cuts 11 are temporarily compressed by this pressure. In the embodiment shown and described herein, this compression occurs at ten different places around the body member 10, namely along both sides of all five cuts.

The spreading and dividing of the pressure and compression permits the body member 10 to absorb such pressure and compression and still return to its original shape when the pressure is released. Without the slits to 

